Comcare v Roser [2003] FCA 243

FEDERAL COURT OF AUSTRALIA

Comcare v Roser [2003] FCA 243

WORKERS COMPENSATION – whether impairments flowing from discrete injuries suffered at different times may be combined under Table 14.1 of the Comcare Guide to produce a single "whole person" impairment percentage – operation and effect of s 24(7) of the Safety Rehabilitation and Compensation Act 1988 (Cth) Safety Rehabilitation and Compensation Act 1988 (Cth) ss 4, 6, 24, 25, 27, 28 Acts Interpretation Act 1901 (Cth) s 23

Brennan v Comcare (1994) 50 FCR 555 followed Comcare v Mihajlovic (2000) 97 FCR 304 referred to Comcare v van Grinsven [2002] FCA 371 referred to COMCARE v DESLIE ROSER No Q 99 of 2002 SPENDER J CANBERRA (heard in Brisbane) 25 MARCH 2003

IN THE FEDERAL COURT OF AUSTRALIA

QUEENSLAND DISTRICT REGISTRY Q 99 OF 2002

BETWEEN: COMCARE

APPLICANT

AND: DESLIE ROSER

RESPONDENT

JUDGE: SPENDER J

DATE OF ORDER: 25 MARCH 2003

WHERE MADE: CANBERRA (heard in Brisbane)

THE COURT ORDERS THAT: 1. The appeal be allowed, and the cross-appeal be allowed in part. 2. The determinations of the Administrative Appeals Tribunal of 29 May 2002 be set aside. 3. There be no order as to costs. Note: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

IN THE FEDERAL COURT OF AUSTRALIA

QUEENSLAND DISTRICT REGISTRY Q 99 OF 2002

BETWEEN: COMCARE

APPLICANT

AND: DESLIE ROSER

RESPONDENT

JUDGE: SPENDER J

DATE: 25 MARCH 2003

PLACE: CANBERRA (heard in Brisbane)

REASONS FOR JUDGMENT 1 Deslie May Roser was an enlisted member of the Australian Army from 16 July 1986 to 20 February 2000. On 15 August 1986 she injured both knees, to which her military service was a contributing factor, and it was determined by a Comcare delegate that the bilateral knee condition resulted in a 20% whole person impairment. On 11 February 1992 she injured her back, which is said to have occurred in work-related circumstances. An assessment of her thoracic lumbar spine condition by a Comcare delegate was that she had a 5% whole person impairment deriving from that injury. 2 Ms Roser contends that she is entitled to receive lump sum compensation on the basis that the percentage values of the levels of impairment for her back injury (5%) and the earlier knee injury (20%) should be combined pursuant to Table 14.1 (Combined Values Chart) of the Guide to the Assessment of the degree of Permanent Impairment ("the Comcare Guide") prepared pursuant to s 28(1) of the Safety, Rehabilitation and Compensation Act 1988 (Cth) ("the Act"), thus increasing her compensable level of whole person impairment from 20% to 24%. 3 Comcare, on the other hand, contend that Ms Roser was entitled to receive lump sum compensation at the level of 20%, being the whole person impairment in respect of the bilateral knee condition which, as a defined injury resulting in greater than 10% whole person impairment, satisfies s 24(1) of the Act. However, Comcare contends that the bilateral knee condition and the back condition are discrete injuries arising out of separate events. Relying on s 24(7) of the Act which provides: "Subject to section 25, where Comcare determines that the degree of permanent impairment of the employee is less than 10%, an amount of compensation is not payable to the employee under this section", Comcare contends that since the thoracic lumbar spine condition involved whole person impairment of less than 10%, no compensation is payable in respect of her back condition. 4 The resolution of these competing contentions is not free from difficulty. The explanatory memorandum in relation to the Act, which came into operation on 1 December 1988 concluded: "While it is not expected that the introduction of the Guide will cause any problems of interpretation or application, its operation will be closely monitored by COMCARE." The many cases which have since had to grapple with the provisions of this Act, and the operation of the Comcare Guide demonstrate the emptiness of that expectation. In Comcare v Mihajlovic (2000) 97 FCR 504 ("Mihajlovic"), Finn J at par 1 referred to: "The less than happy interaction of the Safety, Rehabilitation and Compensation Act 1988 (Cth) (the SRC Act) and the 'Guide to the Assessment of the Degree of Permanent Impairment' (the Guide) prepared under s 28 of that Act …" 5 The present question has not been squarely addressed in earlier cases. It is whether a worker who suffers successive, work-related injuries is entitled to be compensated on the basis of discrete sums in respect of the impairment or impairments that flow from each injury, or whether the entitlement is to be a single sum, based on the combined effect of all the impairments that flow from both of the injuries. 6 The application comes before the Federal Court in the following way. On 29 May 2002, the Administrative Appeals Tribunal ("the Tribunal") constituted by Mr I.R. Way, Member, made a decision in an application for review instituted by Deslie May Roser ("Ms Roser"). I note that Ms Roser sought review using her full name, but in the reasons for decision of the Tribunal and in this application, she is identified only by her first and surname. The application sought review of a decision which the Military Compensation and Rehabilitation Service, as delegate of Comcare, made on 12 April 2001 under the Act, which affirmed an earlier decision on 22 November 2000 disallowing Ms Roser's claim for additional lump sum compensation for what she claims was the one permanent impairment arising from her combined bilateral knee condition and back condition. 7 On 23 February 2001, the solicitors for Ms Roser had made a request under s 62(3) of the Act for a reconsideration of the decision of 22 November 2000, which was based on the view of the delegate that Table 14.1 was not applicable in Ms Roser's case. The decision of Comcare of 12 April 2001, in affirming the determination made on 22 November 2000, rejected the contention that Table 14.1 was applicable. 8 On 29 May 2002 the Tribunal set aside the decision under review and determined: "(a) that the applicant's rate of permanent impairment is assessed at 24%; and (b) that the increase in the degree of the applicant's permanent impairment, as a result of her back injury is 4% and no further amounts of compensation are payable to the applicant in respect of this increase in permanent impairment." 9 By this decision Ms Roser failed in her bid to the Tribunal to have her lump sum compensation for permanent impairment increased above that already paid to her. Comcare appealed against the Tribunal's decision by filing a notice of appeal on 25 June 2002, and Ms Roser responded by filing a notice of cross-appeal on 19 July 2002. 10 The hearing before the Tribunal proceeded by way of written submissions only, on a statement of agreed facts. The agreed facts, as corrected by the substitution of a correct date, are as follows: "1. The Applicant is thirty-three years of age having been born on 1 June 1968. She enlisted in the Australian Army on 16 July 1986 and was discharged on medical grounds on 20 February 2000. She attained the rank of Corporal. 2. On 30 August 1999 the Applicant lodged a claim for compensation in respect of a 'left and right knee' condition, claimed to have resulted from basic training and work-related activities. On 8 November 1999 a delegate of the Respondent determined that the Applicant has suffered a contraction of a disease to which military service was a contributing factor, namely, tears of the front half of both lateral menisci and degenerative changes to both knees. The date of the injury for the purposes of the Act was determined as 15 August 1986. 3. On 4 January 2000 the Applicant made application for lump sum payment of compensation for permanent impairment in respect of the bilateral knee condition. By 7 March 2000 a delegate of the Respondent determined that the Applicant had a 20% whole person impairment in respect of the bilateral knee condition. 4. On 7 March 2000, the Respondent having made a final assessment of the degree of permanent impairment suffered by the Applicant, informed the Applicant that the amount of $35,758.34 (less some minor reductions) was payable by way of lump sum in respect of a permanent impairment arising from her bilateral knee condition. 5. On 8 March 2000, the Applicant elected to receive the sum of lump sum compensation referred to above for permanent impairment. 6. On 30 August 1999 the Applicant lodged a claim for compensation in relation to a back condition, claimed to have resulted from an injury which occurred in work-related circumstances on 11 February 1992. 7. On 28 April 2000 a delegate of the Respondent determined that the Applicant had suffered a contraction of a disease to which military service had contributed in a material degree, namely, thoracic spondylosis. The Applicant applied for lump sum compensation for permanent impairment in respect of the said condition. 8. On 31 May 2000 a delegate of the Respondent determined that there was no liability to pay lump sum compensation for permanent impairment for a thoracic spondylosis condition. 9. The Applicant requested a reconsideration of that decision and, in support of that request, provided a report of Dr Parsons, Orthopaedic Surgeon, dated 12 August 2000. In that report Dr Parsons assessed the Applicant as having a 5% whole person impairment deriving from her thoracic lumbar spine condition pursuant to Table 9.6 of the Comcare Guide. 10. On 22 November 2000 a delegate of the Respondent affirmed the decision under review." 11 The Tribunal posed for itself the questions it had to answer as follows: "(a) Does the fact that the impairment to the applicant's back arose from a different cause to the impairment to her knees preclude the use of the combined values table in the Comcare Guide; (b) If not, does the fact that the impairment to the applicant's back being less than 10% preclude the use of the combined table; and (c) If not, is a further amount of compensation payable to the applicant in respect of a subsequent increase in the degree of impairment." 12 The relevant provisions of the Act, the Comcare Guide and the Acts Interpretation Act 1901 (Cth) are: "Safety Rehabilitation and Compensation Act 1988 Interpretation 4 (1) In this Act, unless the contrary intention appears: 'approved Guide' means: (a) the document, prepared by Comcare in accordance with section 28 under the title 'Guide to the Assessment of the Degree of Permanent Impairment', that has been approved by the Minister and is for the time being in force; and (b) if an instrument varying the document has been approved by the Minister – that document as so varied; 'disease' means: (a) any ailment suffered by an employee; or (b) the aggravation of any such ailment; being an ailment or an aggravation that was contributed to in a material degree by the employee's employment by the Commonwealth or a licensed corporation; 'impairment' means the loss, the loss of the use, or the damage or malfunction, of any part of the body or of any bodily system or function or part of such system or function; 'injury' means: (a) a disease suffered by an employee; or (b) an injury (other than a disease) suffered by an employee, being a physical or mental injury arising out of, or in the course of, the employee's employment; or (c) an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee's employment), being an aggravation that arose out of, or in the course of, that employment; but does not include any such disease, injury or aggravation suffered by an employee as a result of reasonable disciplinary action taken against the employee or failure by the employee to obtain a promotion, transfer or benefit in connection with his or her employment; 'permanent' means likely to continue indefinitely; Injury arising out of or in the course of employment 6 (1) Without limiting the circumstances in which an injury to an employee may be treated as having arisen out of, or in the course of, his or her employment, an injury shall, for the purposes of this Act, be treated as having so arisen if it was sustained: … (b) while the employee: (i) was at his or her place of work, for the purposes of that employment, or was temporarily absent from that place during an ordinary recess in that employment; Compensation for injuries resulting in permanent impairment 24 (1) Where an injury to an employee results in a permanent impairment, Comcare is liable to pay compensation to the employee in respect of the injury. (2) For the purposes of determining whether an impairment is permanent, Comcare shall have regard to: (a) the duration of the impairment; (b) the likelihood of improvement in the employee's condition; (c) whether the employee has undertaken all reasonable rehabilitative treatment for the impairment; and (d) any other relevant matters … (4) The amount assessed by Comcare shall be an amount that is the same percentage of the maximum amount as the percentage determined by Comcare under subsection (5). (5) Comcare shall determine the degree of permanent impairment of the employee resulting from an injury under the provisions of the approved Guide. … (7) Subject to section 25, if: (a) the employee has a permanent impairment other than a hearing loss; and (b) Comcare determines that the degree of permanent impairment is less than 10%; an amount of compensation is not payable to the employee under this section." [Subsection 24(9) prescribes the maximum amount for the purposes of s 24.] "Interim payment of compensation 25 (1) Where Comcare: (a) makes a determination that an employee is suffering from a permanent impairment as a result of an injury; and (b) is satisfied that the degree of impairment is equal to or more than 10% but has not made a final determination of the degree of impairment; Comcare shall, on the written request of the employee made at any time before the final determination is made, make an interim determination of the degree of permanent impairment under section 24 and assess an amount of compensation payable to the employee. (2) The amount assessed by Comcare under subsection (1) shall be an amount that is the same percentage of the maximum amount specified in subsection 24(9) as the percentage determined by Comcare under subsection (1) to be the degree of permanent impairment of the employee. (3) Where, after an amount of compensation has been paid to an employee following the making of an interim determination, Comcare makes a final determination of the degree of permanent impairment of the employee, there is payable to the employee an amount equal to the difference (if any) between the amount payable under section 24 on the making of the final determination and the amount paid to the employee under this section. (4) Where Comcare has made a final assessment of the degree of permanent impairment of an employee (other than hearing loss), no further amounts of compensation shall be payable to the employee in respect of subsequent increase in the degree of impairment, unless the increase is 10% or more. Approved Guide 28 (1) Comcare may, from time to time, prepare a written document, to be called 'the Guide to the Assessment of the Degree of Permanent Impairment', setting out: (a) criteria by reference to which the degree of the permanent impairment of an employee resulting from an injury shall be determined; (b) criteria by reference to which the degree of a non-economic loss suffered by an employee as a result of an injury or impairment shall be determined; and (c) methods by which the degree of permanent impairment and the degree of non-economic loss, as determined under those criteria, shall be expressed as a percentage. Comcare Guide Impairment means 'the loss, loss of use, damage or malfunction, of any part of the body, bodily system or function or part of such system or function'. It relates to the health status of an individual and includes anatomical loss, anatomical abnormality, physiological abnormality and psychological abnormality. Throughout this guide emphasis is given to loss of function as a basis of assessment of impairment and as far as possible objective criteria have been used. The Impairment Tables Part A of the Guide is based on the concept of 'whole person impairment' which is drawn from the American Medical Association's Guides. Evaluation of a whole person impairment is a medical appraisal of the nature and extent of the effect of an injury or disease on a person's functional capacity and activities of daily living. As with the American Medical Association's Guides, Part A of this guide is structured by assembling detailed descriptions of impairments into groups according to body system and expressing the extent of each impairment as a percentage value of the functional capacity of a normal healthy person. Thus a percentage value can be assigned to an employee's impairment by reference to the relevant description in this guide. Combined Impairments It is important to realise that impairment is system or function based and that a single injury or disease may give rise to multiple loss of function. When more than one table applies to a single injury separate scores should be allocated to each functional impairment. Where two or more injuries give rise to the same impairment a single rating only should be given. (Emphasis added) Double Assessment The possibility of double assessment for a single loss of function must be guarded against. For example, it would be inappropriate to assess a lower limb amputation by reference to both the amputation table (9.3) and the lower extremity table (9.2). Where an employee suffers from more than one impairment the values are not added but are combined using the Combined Values Table. The purpose of this table is to give the total effect of all impairments, according to a formula, as a percentage value of the employee's whole bodily system or function (see Table 14). (Emphasis added) Interim Assessments To ensure that the possibility of entitlement to a permanent impairment payment does not impede the rehabilitation process provision is made for interim assessment and payment of compensation. Assessment for an interim payment will apply mainly in cases undergoing active treatment where the final outcome of the treatment is not known but a minimum permanent impairment can be measured. Care should be taken to ensure that further treatment will not reduce the impairment which must be at least 10%. Interim payment will generally not apply where the impairment has stabilised or where the only change in impairment would be due to progressive degeneration. Acts Interpretation Act 1901 (Cth) Rules as to gender and number 23 In any Act, unless the contrary intention appears (a) words importing a gender include every other gender; and (b) words in the singular number include the plural and words in the plural number include the singular." 13 The grounds of the amended notice of appeal are: "(a) In construing section 24(5) of the Safety Rehabilitation and Compensation Act 1988, the Tribunal erred in ruling that the use of the words 'an injury' in that section and the use of the singular throughout the said Act were such as to not exclude the operation of section 23 of the Acts Interpretation Act 1901; (b) The Tribunal erred in ruling that Table 14.1 of the Guide applied to circumstances in which separate work-related injuries with consequent discrete impairments have arisen from different work-related incidents. (c) The Tribunal erred in failing to find that the loss of use of the Respondent's body resulting from the injuries to her knees sustained in August 1986 and the loss of use of the Respondent's body resulting from the injury to her back sustained in February 1992 give rise to separate permanent impairments for the purposes of section 25(4) of the Safety Rehabilitation and Compensation Act 1988; (d) The Tribunal erred in failing to find that the injuries to the Respondent's knees sustained in August 1986 and the injury to the Respondent's back sustained in February 1992 give rise to separate legal liabilities to pay compensation pursuant to section 24(1) of the Safety, Rehabilitation and Compensation Act 1988." 14 The cross-appeal seeks orders: "(1) That that part of the decision of the Tribunal whereby it was determined that the increase in the degree of the Respondent's permanent impairment as a result of her back injury is 4% and no further amounts of compensation are payable to the Respondent in respect of that increase in permanent impairment be set aside; (2) That a decision be substituted that the Respondent is entitled to payment of compensation pursuant to section 24 of the Safety Rehabilitation and Compensation Act 1988 on the basis that she has a 24% permanent impairment." 15 The grounds of the cross-appeal are: "(1) In construing section 25(4) of the Safety Rehabilitation and Compensation Act 1988, the Tribunal erred in finding that a "final assessment" of the level of impairment suffered by the Respondent arising out of her bilateral knee condition had been made by the Applicant, within the meaning of the section; and (2) The Tribunal erred in finding that the election by the Respondent to accept a payment of lump sum compensation in respect of a 20% permanent impairment attributable to her bilateral knee condition precluded her from receiving compensation attributable to a 24% permanent impairment arising out of her bilateral knee condition and her back injury." 16 Concerning as the cross-appeal, Comcare submits that if its appeal succeeds the cross-appeal must fail. This is because s 24(7) would preclude compensation in respect of the separate permanent impairment attributable to Ms Roser's back condition. However, Comcare acknowledges that if it fails on its appeal and the Court consequently does not make any order displacing the assessment of degree of permanent impairment at 24% (which assessment was made on the footing that the relevant permanent impairment which Comcare must assess under s 24(5) is the permanent impairment attributable to both the knee injury and the back injury taken together), the amount of compensation payable would fall to be assessed on a basis of the 24% pursuant to s 24(4). Comcare does not seek to support the conclusion of the Tribunal that s 25(4) would operate to preclude liability to pay further compensation, notwithstanding its finding that the applicable degree of permanent impairment is 24%. 17 Comcare therefore accepts that if it succeeds in its appeal the cross-appeal must fail, but that if it is unsuccessful in its appeal the cross appeal must be successful. Both parties agree that the second finding of the Tribunal, namely "that the increase in the degree of the applicant's permanent impairment, as a result of her back injury is 4% and no further amounts of compensation are payable to the applicant in respect of this increase in permanent impairment" cannot be supported. 18 I turn then to a consideration of the appeal by Comcare. 19 The notification letter by Comcare made on 12 April 2001 expressed its reasons why Table 14.1 was inapplicable. That letter said in part: "In your case I note that you have suffered two separate compensable injuries, namely: · 'tears front half of both lateral menisci and degenerative changes, both knees' with deemed date of injury 15 August 1986, this being the date you first sought medical treatment for this condition; and · 'thoracic spondylosis' which occurred on 11 February 1992, and for which treatment was first received on 17 February 1992. Subsection 24(1) of the SRCA states that you are entitled to compensation if a compensable injury has resulted in a permanent impairment. Subsections 24(2) to 24(7) of the SRCA provide further assistance in determining whether or not that entitlement exists. These subsections state that: '(2) For the purpose of determining whether an impairment is permanent Comcare shall have regard to: (a) the duration of the impairment; (b) the likelihood of improvement in the employee's condition; (c) whether the employee has undertaken all reasonable rehabilitative treatment for the impairment; and (d) any other relevant matters. (3) Subject to this section, the amount of compensation payable to the employee is such amount, as is assessed by Comcare under subsection (4), being an amount not exceeding the maximum amount at the date of the assessment. (4) The amount assessed by Comcare shall be an amount that is the same percentage of the maximum amount as the percentage determined by Comcare under subsection (5). (5) Comcare shall determine the degree of permanent impairment of the employee resulting from an injury under the provisions of the approved Guide. (6) The degree of permanent impairment shall be expressed as a percentage. (7) Subject to section 25, where Comcare determines that the degree of permanent impairment of the employee is less than 10%, an amount of compensation is not payable to the employee under this section'." [I note that what is said to be subs 7 is in fact a summary of that provision.] "The applicable legislation therefore establishes that an employee is entitled to compensation for permanent impairment under section 24 of the SRCA where they have suffered a compensable injury that has resulted in an impairment that can be considered permanent and has been assessed as amounting to a 10% or greater whole person impairment under the approved Guide. I am also satisfied that as the entitlement to compensation derives from subsection 24(1) of the SRCA any such claim for permanent impairment compensation must flow from a defined 'injury'. In your situation you have suffered two separate compensable injuries and as such any claim for permanent impairment compensation under section 24 of the SRCA must also be dealt with in a separate manner." 20 In this case, two separate applications were made for compensation in respect of discrete injuries arising out of discrete events. Each application for compensation was made coincidentally on the same day, namely 30 August 1999. 21 On one view of the Act, the view for which Comcare contends, if Ms Roser had applied for compensation pursuant to the Act in respect of the condition of her knees shortly after sustaining those injuries or shortly after those injuries had stabilised and had received a lump sum compensation for the condition of her knees, she would not be entitled to any sum by way of compensation in respect of the back injury sustained as a result of a much later incident. This is because in respect of that injury s 24(7) would apply, the degree of impairment of bodily function as a result of the back injury not exceeding 10%. 22 Does the circumstance that an application for compensation in respect of the condition of her knees had not been determined when the application in respect of her back condition was made, have the consequence that the amount of compensation is to be assessed as a single global figure for both injuries, by reference to Table 14.1, even if as here, the injuries occurred at different times? This is the contention of the respondent. 23 It would be consistent with the view of the Act for which the respondent contends that, if a party had received a lump sum for compensation for a particular injury or injuries, and then later sustained a further injury which resulted in further impairment, then it would not matter whether that further impairment was below or exceeded 10%: the combined whole body impairment would have to be found and that person entitled to payment of the difference between the compensation applicable to that combined impairment and the compensation previously paid. 24 Section 24(1) of the Act is the source of the statutory entitlement to compensation for permanent impairment. As Burchett J noted in Brennan v Comcare (1994) 50 FCR 555, ("Brennan") "compensation… is paid 'in respect of the injury', not in respect of the impairment",at 556. For a liability to arise there must, in my view, be an injury and it must result in a permanent impairment. A clear cause and effect relationship between the injury and permanent impairment is posited and required. 25 The word "injury" is defined in s 4 of the Act in terms of a disease; or a physical or mental injury (other than a disease) being a physical or mental injury arising out of or in the course of the employee's employment; or an aggravation thereto suffered by the employee. The expression "permanent impairment" is not defined, but its components are. The word "permanent" means likely to continue indefinitely and the word "impairment" means the loss, the loss of the use, or the damage or malfunction, of any part of the body or of any bodily system or function or part of such system or function. It follows from the definition of "impairment" in s 4 that the loss of use of one part of the body is an impairment distinct and different from the loss of use of another part of the body, and likewise, the loss and use of one bodily function or system is an impairment distinct and different from the loss of use of another bodily function or system. 26 In Mihajlovic, Finn J noted at par 12 that "Miraslava Mihajlovic suffered work-related injuries from an incident in 1991, for which Comcare accepted liability." There were thus a number of injuries which arose from a single incident. "… (ii) Ms Mihajlovic was assessed in 1992 as having a 28% degree of whole body impairment, this being a composite value of the following three impairments calculated under their respective designated table: · Upper limb function due to right shoulder and arm pain: 10 per cent – Table 9.4 · Sciatica: 10 per cent – Table 9.5 · Lumbar spondylosis: 10 per cent – Table 9.6 (iii) it is apparent, as the Tribunal found, that if Table 14.1 had been applied correctly to the above percentages, the combined value ought to have been 27 per cent, not 28 per cent." 27 Mihajlovic was concerned with the proper construction of s 25(4) of the Act, and Finn J concluded that s 25(4) applied to determinations made under s 24 and that on the proper construction of s 25(4) there has to be a 10 % increase in the degree of impairment of an employee (after applying Table 14.1 in cases of multiple impairments), even if one particular impairment has increased by 10 per cent. It is not sufficient that one particular impairment has increased by 10 per cent. 28 Finn J noted: " The Tribunal [had] concluded that in determining an employee's degree of permanent impairment for the purpose of calculating compensation under s 24, a combined assessment under Table 14.1 was to be made of all of the employee's impairments whether or not those impairments arose out of the same or different injuries. The parties, I would note, have not put this interpretation of s 24 in issue and I express no opinion on it (though by so doing I imply no criticism of it)." His Honour thus flagged an important aspect of the current question. 29 I accept that the word "injury" in s 24(1) and 24(5) may include "injuries". 30 In Johns v Connor (1992) 107 ALR 465 at 473, Lockhart J said: "The purpose of s 23 [of the Acts Interpretation Act 1901 (Cth)]and the principles that govern its application have been referred to in many cases, but the following oft cited passage from the judgment of the Judicial Committee of the Privy Council in Blue Metal Industries Ltd v Dilley [1970] AC 827 at 846-7 is apt: 'By s 21 of the Interpretation Act, 1899 (NSW), it is enacted that in all Acts, unless the contrary intention appears, words in the singular shall include the plural and words in the plural shall include the singular. Such a provision is of manifest advantage. It assists the legislature to avoid cumbersome and over-elaborate wording. Prima facie it can be assumed that in the processes which lead to an enactment both draughtsman and legislators have such a provision in mind. It follows that the mere fact that the reading of words in a section suggests an emphasis on singularity as opposed to plurality is not enough to exclude plurality. Words in the singular will include the plural unless the contrary intention appears. But in considering whether a contrary intention appears there need be no confinement of attention to any one particular section of an Act. It must be appropriate to consider the section in its setting in the legislation and furthermore to consider the substance and tenor of the legislation as a whole. (See Sin Poh Amalgamated (HK) Ltd v Attorney-General of Hong Kong [1965] 1 WLR 62). In that case a test was indicated which often may be helpful. In the judgment of the board delivered by Lord Pearce it was said, at 67: The Interpretation Ordinance was intended to avoid multiplicity of verbiage and to make the plural cover the singular except in such cases as one finds in the context of the legislation reason to suppose that the legislature, if offered such amendment to the bill, would have rejected it.'" 31 However, in my opinion, the Act is based on the notion that each work related injury creates a liability in the Commonwealth to pay compensation. 32 In my opinion, where there are discrete incidents, each resulting in injury or injuries, the Act does not contemplate a single whole person impairment, to be arrived at by considering the combined effect of the separate whole person impairments attributable to each set of injuries. 33 Gummow J in Brennan said at 565: "Section 24 … imposes a liability upon Comcare to pay compensation in respect of an injury which results in a permanent impairment. The compensation is to be in an amount which reflects the degree, expressed as a percentage, of permanent impairment of the employee resulting from the injury. The maximum amount for the purposes of the section is $80,000." And later at 566: "Section 24 imposes a liability upon Comcare where 'an injury to an employee results in a permanent impairment'. [Emphasis supplied] A 'permanent impairment', as a result of separate definitions of those terms in s 4, means the loss, or the loss of use, or the damage or malfunction, of any part of the body or of any bodily system or function or part of such system or function, which in any such case 'is likely to continue indefinitely'. 'For the purpose of determining whether an impairment is permanent', Comcare is obliged by s 24(2) to have regard to: '(a)the duration of the impairment; (b) the likelihood of improvement in the employee's condition; (c) whether the employee has undertaken all reasonable rehabilitative treatment for the impairment; and (d) any other relevant matters.'" [Emphasis supplied] 34 In the view I take of the matter, where an injury or more than one injury is caused as the result of a single event or incident, s 24 provides the means by which the whole person impairment flowing as a result of each injury is to be determined. However, a number of discrete injuries, suffered sequentially, may result in the same impairment. Comcare v Van Grinsven [2002] FCA 371 ("van Grinsven") was such a case. The point in issue in the present case was not taken in that case. Mr van Grinsven injured his left knee on 17 December 1985 whilst undertaking basic training activities in the Royal Australian Army, and he injured his right knee in similar activities on 7 February 1986. He made separate claims for compensation, one in relation to each knee. The Tribunal held that although each injury led to the same impairment assessed under Table 9.5 at 20%, this rating should be assessed for each knee and combined as two degrees of impairment under Table 14 so as to give an assessment of 36%. 35 The Full Court of the Federal Court (Beaumont, Finn and Sundberg JJ) held that Table 9.5 constituted a self-contained assessment approach alternative to the combined singular injury assessment method in Table 9.2 , and for the purpose of that table, the respondent did not suffer from more than one impairment. The Court said at par 16: "It is clear that for the purpose of Table 9.5 the respondent does not suffer from more than one impairment. He may suffer from two knee injuries, but for the purpose of Table 9.5 these only give rise to the one impairment, that is, 'Can rise to standing position and walk but has difficulty with grades, steps and distances'. Thus Dr Pentis' assessment is that the respondent has a 20 per cent 'whole person impairment' and Ms Bertoldi's assessment is that he has an 'overall level of lower limb impairment' of 20 per cent. By way of contrast, for the purpose of Table 9.2 he can be said to have multiple impairments. In Table 9.2 each single joint injury is an impairment. That is why it is necessary to use Table 14.1 to combine these impairments in order to obtain the whole person impairment percentage." 36 Ms Roser's knee injuries, on the evidence, appear to have been sustained at the same time and in the same circumstances. The condition of each knee gives rise to the same functional impairment as provided by Table 9.5. Ms Roser therefore was entitled to be compensated for her bilateral knee condition on the basis of a whole person impairment of 20%. Van Grinsven seems to have proceeded on the basis that it was competent to consider separate injuries arising on separate occasions, the Tribunal and the Full Court on appeal assessing Mr van Grinsven's entitlement having regard to both injuries. That is what the respondent in the present appeal seeks to do. 37 In the view I take of the matter, if there are two incidents, each involving injury or injuries, there are discrete liabilities for each injury, the extent of which has to be determined discretely. A single injury may result in multiple impairments (which then have to be "combined" under Table 14.1), and multiple injuries may result in a single impairment. An example of the latter is the injuries sustained to Ms Roser's knees in 1986. 38 The submissions by Ms C.C. Heyworth-Smith of counsel on behalf of the respondent are beguilingly straightforward. She submitted on behalf of Ms Roser that whilst s 24(5) speaks of "an injury", there is nothing in the section or in the context of the section or in the Act as a whole which would displace the presumption afforded by s 23 of the Acts Interpretation Act 1901 (Cth). 39 As a consequence, it was submitted on the respondent's behalf that s 24(5) of the Act permits it to be read as: "Section 24(5) Comcare shall determine the degree of permanent impairment of the employee resulting from injuries under the provisions of the approved Guide." Counsel for the respondent acknowledges that the incidents or events causing the injury to her knees in August 1986 and to her back in February 1992 were separate and unconnected. Nonetheless, it was submitted: "… her injuries have led to an impairment to her 'whole person'. The level of that impairment is ascertained by the use of Table 14.1, the Combined Values Chart". 40 Contrary to the submissions that were made on behalf of Comcare by Mr R.W. Gotterson QC of counsel, counsel for the respondent submitted: "There is no reason why a distinction should be drawn between: i. a case involving one incident leading to two injuries and to two impairments (as in Mihajlovic); and ii. a case involving two incidents leading to two injuries and to two impairments (as in the present case)."